Finding FE, Tension & Acceleration in a 3-Block Frictionless Ramp Setup

In summary, three blocks with masses of 1.00 kg, 2.00 kg, and 3.00 kg are held together on a frictionless 45° ramp by massless ropes. The force FE is exerted on the top block to keep all the blocks in place. In the first scenario, the force of gravity on the top block causes a tension in the rope equal to the force of gravity on the combined mass of 5 kg. In the second scenario, when FE is no longer acting on the blocks, they slide down the ramp and the tension in the rope is equal to the force of gravity on the 3 kg mass. In the third scenario, with 2FE acting on the top block
  • #1
watever
1
0
three blocks on a frictionless 45° ramp held together by massless ropes
top block's mass, m1=1.00 kg.
middle block's mass, m2=2.00 kg
bottom block's mass, m3=3.00 kg.
1. the force 'FE' is exerted on block one and is just enough to hold all the blocks in place
find FE and the tensions of the ropes
2. FE is no longer acting on the blocks so they slide down the ramp, find the acceleration of the blocks and the tensions in the ropes
3. 2FE is now acting on block one, find acceleration of blocks and tensions in the ropes


All I really need help with is the tension
 
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  • #2
Basically it's the force coming from the rope

So for example, the top block is sitting still for part 1 and has what amounts to 5kg of mass hanging on that segment of rope. Figure out the force of gravity going down the incline caused by the 5kg, that force will be the tension in the rope, it's how much force the rope has to apply to hold them there

The tension in the other segment(connecting blocks 2 and 3), well that segment of rope is only supporting the 3 kg mass
 
  • #3


I would approach this problem by first drawing a free-body diagram for each block and analyzing the forces acting on them. Since the ramp is frictionless, the only forces acting on the blocks are the gravitational force (mg) and the tension forces from the ropes.

1. To find the force FE, we can use the fact that it is just enough to hold all the blocks in place. This means that the net force on the blocks is zero, so the tension forces in the ropes must balance out the gravitational force. Using this information, we can set up the following equations:

For block 1:
FE = T1sin45°

For block 2:
T1sin45° = T2sin45° + m2g

For block 3:
T2sin45° = T3sin45° + m3g

Solving these equations simultaneously, we can find the value of FE and the tensions in the ropes.

2. When FE is no longer acting on the blocks and they start sliding down the ramp, the net force on each block will be equal to their respective mass times the acceleration (F = ma). We can set up the following equations:

For block 1:
T1sin45° = m1a

For block 2:
T2sin45° = m2a

For block 3:
T3sin45° = m3a

Solving these equations simultaneously, we can find the acceleration of the blocks and the tensions in the ropes.

3. When 2FE is now acting on block one, the net force on block one will be equal to its mass times the acceleration, and the net force on blocks 2 and 3 will be equal to their respective mass times the acceleration plus the tension force from the ropes. We can set up the following equations:

For block 1:
2FE - T1sin45° = m1a

For block 2:
T1sin45° - T2sin45° = m2a

For block 3:
T2sin45° - T3sin45° = m3a

Solving these equations simultaneously, we can find the acceleration of the blocks and the tensions in the ropes.

In conclusion, by carefully analyzing the forces acting on the blocks and using Newton's laws of motion, we can find the tension forces in the ropes and the acceleration of the blocks in each scenario. This approach can be
 

FAQ: Finding FE, Tension & Acceleration in a 3-Block Frictionless Ramp Setup

What is the purpose of finding FE, tension, and acceleration in a 3-block frictionless ramp setup?

The purpose of finding FE, tension, and acceleration in a 3-block frictionless ramp setup is to understand the principles of Newton's Laws of Motion and to apply them in a real-world scenario. This setup allows scientists to study the relationship between forces, acceleration, and tension in a controlled and simplified environment.

How is the force of gravity related to the acceleration of the blocks on the ramp?

The force of gravity is directly related to the acceleration of the blocks on the ramp. According to Newton's Second Law of Motion, the force acting on an object is equal to its mass multiplied by its acceleration. In this setup, the force of gravity is the only force acting on the blocks, so it is equal to the mass of the blocks multiplied by their acceleration.

What role do friction and air resistance play in this setup?

In a frictionless ramp setup, neither friction nor air resistance play a role. Friction is a force that opposes motion between two surfaces in contact, and air resistance is a force that opposes the motion of an object through air. In this setup, both of these forces are eliminated in order to isolate and study the effects of other forces, such as gravity and tension.

How does the angle of the ramp affect the tension and acceleration of the blocks?

The angle of the ramp can affect the tension and acceleration of the blocks. As the angle of the ramp increases, the force of gravity acting on the blocks also increases, resulting in a greater tension and acceleration of the blocks. This relationship is described by the equation T = mg sinθ, where T is the tension, m is the mass of the block, g is the acceleration due to gravity, and θ is the angle of the ramp.

Can this setup be used to study other concepts in physics?

Yes, this setup can be used to study other concepts in physics, such as kinetic and potential energy, work, and power. By altering the variables in the setup, such as the mass of the blocks or the angle of the ramp, scientists can observe and analyze the effects on these other concepts. This can lead to a better understanding of how different forces and motions interact and affect each other.

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